System and method of companding an input signal of an energy detecting receiver

ABSTRACT

An apparatus configured as a compandor to achieve a defined dynamic range for an output signal in response to an input signal. In particular, the apparatus comprises a first circuit adapted to generate a first signal from the input signal, wherein the first signal includes a first dynamic range (e.g., a first sensitivity and first compression point); and a second circuit adapted to generate a second signal from the input signal, wherein the second signal includes a second dynamic range (e.g., a second sensitivity and second compression point) that is different from the first dynamic range of the first signal. The apparatus may further include a third circuit adapted to generate an output signal related to a sum of the first and second signals. By adjusting the first and second dynamic ranges, an overall dynamic range for the output signal of the companding apparatus may be achieved.

BACKGROUND

1. Field

The present disclosure relates generally to communications systems, andmore specifically, to system and method of companding an input signal ofan energy detecting receiver.

2. Background

Communications devices that operate on limited power supplies, such asbatteries, typically use techniques to provide the intendedfunctionality while consuming relatively small amounts of power. Onetechnique that has been gaining in popularity relates to receivingsignals using pulse modulation techniques. This technique generallyinvolves receiving information using low duty cycle pulses and operatingin a low power mode during times when not receiving the pulses. Thus, inthese devices, the power efficiency is typically better thancommunications devices that continuously operate a receiver.

Usually, energy detecting receivers are employed when using pulsemodulation techniques. In such receiver, the input signal is typicallyapplied to a non-linear device, such as a substantially squaring device,in order to detect the incoming pulses. However, the non-linear orsquaring device generally increases the dynamic range of the inputsignal by a factor of two (2) as measured in decibels (dB). Because ofthe substantial increase in the dynamic range of the input signal, thepower level of the input signal should be controlled in order to preventcompression or, conversely, falling below the sensitivity of subsequentreceiving stages.

In the past, automatic gain circuits (AGC) have been employed in orderto address the relatively large dynamic range of the input signalgenerated at the output of the non-linear or squaring device. In suchapplication, the AGC circuit is configured to partition the dynamicrange into several overlapping windows, and requires sophisticated andfast circuitry to maintain the received signal level within the properwindow. For instance, if the wrong window is selected for theinstantaneous level of the received signal, then information may be lostby either the receiver going into compression or conversely droppingbelow the receiver's sensitivity. Further to the speed and accuracyrequirements of the AGC circuit, there is the requirement of theoverlapping windows. To minimize overlap and therefore the number of AGCwindows, tight receiver gain tolerances are typically required, whichleads to complex, costly, and power consuming circuits.

SUMMARY

An aspect of the disclosure relates to an apparatus that may beconfigured as a compandor to achieve a defined dynamic range for anoutput signal from an input signal. In particular, the apparatuscomprises a first circuit adapted to generate a first signal from aninput signal, wherein the first signal includes a first dynamic range;and a second circuit adapted to generate a second signal from the inputsignal, wherein the second signal includes a second dynamic range thatis different from the first dynamic range of the first signal. Inanother aspect, the apparatus may comprise a third circuit adapted togenerate an output signal related to a sum of the first and secondsignals. By adjusting the first and second dynamic ranges, an overalldynamic range for the output signal of the companding apparatus may beachieved.

In another aspect, the first circuit is configured to have a firstsensitivity or gain in generating the first signal from the inputsignal. In another aspect, the second circuit is configured to have asecond sensitivity or gain in generating the second signal from theinput signal, wherein the second sensitivity or gain of the secondcircuit is different than the first sensitivity or gain of the firstcircuit. Additionally, in another aspect, the first circuit may beconfigured to have a first compression point or threshold, and thesecond circuit is configured to have a second compression point orthreshold that is different from the first compression point orthreshold of the first circuit.

In yet another aspect, the apparatus comprises a fourth circuit foradjusting the first and/or second dynamic ranges of the first and secondcircuits, respectively. In another aspect, the fourth circuit is adaptedto generate a reference voltage or current for the first and/or thesecond circuits, respectively. The reference voltage or current adjustthe dynamic range characteristic of the first and/or second circuits. Inanother aspect, the fourth circuit comprises a programmable referencelevel device adapted to generate the first or second reference voltage.

In yet another aspect, the first or second circuit may comprise anenvelope detector, a squaring device, a differential transistor pair, ora differential amplifier. In another aspect, the first circuit comprisesa first transistor pair with transistors of a first size, and the secondcircuit comprises a second transistor pair with transistors of a secondsize different than the first size of the transistors of the firsttransistor pair. In still another aspect, the apparatus comprises firstand second current sources adapted to provide first and second referencecurrents for the first and second transistor pair. In also anotheraspect, the first or second circuit is adapted to have a fractionalbandwidth on the order of 20% or more, a bandwidth on the order of 500MHz or more, or a fractional bandwidth on the order of 20% or more and abandwidth on the order of 500 MHz or more.

Other aspects, advantages and novel features of the present disclosurewill become apparent from the following detailed description of thedisclosure when considered in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a block diagram of an exemplary compandor inaccordance with an aspect of the disclosure.

FIG. 2 illustrates a graph of an exemplary input-output response of theexemplary compandor in accordance with another aspect of the disclosure.

FIG. 3 illustrates a block diagram of another exemplary compandor inaccordance with another aspect of the disclosure.

FIG. 4 illustrates a block diagram of yet another exemplary compandor inaccordance with another aspect of the disclosure.

FIG. 5 illustrates a block diagram of an exemplary communications devicein accordance with another aspect of the disclosure.

FIG. 6 illustrates a block diagram of another exemplary communicationsdevice in accordance with another aspect of the invention.

FIGS. 7A-D illustrate timing diagrams of various pulse modulationtechniques in accordance with another aspect of the disclosure.

FIG. 8 illustrates a block diagram of various communications devicescommunicating with each other via various channels in accordance withanother aspect of the disclosure.

FIG. 9 illustrates a block diagram of another exemplary compandor inaccordance with another aspect of the disclosure.

DETAILED DESCRIPTION

Various aspects of the disclosure are described below. It should beapparent that the teachings herein may be embodied in a wide variety offorms and that any specific structure, function, or both being disclosedherein are merely representative. Based on the teachings herein oneskilled in the art should appreciate that an aspect disclosed herein maybe implemented independently of any other aspects and that two or moreof these aspects may be combined in various ways. For example, anapparatus may be implemented or a method may be practiced using anynumber of the aspects set forth herein. In addition, such an apparatusmay be implemented or such a method may be practiced using otherstructure, functionality, or structure and functionality in addition toor other than one or more of the aspects set forth herein. Furthermore,an aspect comprise at least one element of a claim.

As an example of some of the above concepts, in some aspects, thedisclosure relates to an apparatus configured as a compandor to achievea specified dynamic range for an output signal in response to an inputsignal dynamic range. In particular, the apparatus comprises a firstcircuit adapted to generate a first signal from the input signal,wherein the first signal includes a first dynamic range (e.g., a firstsensitivity and first compression point); and a second circuit adaptedto generate a second signal from the input signal, wherein the secondsignal includes a second dynamic range (e.g., a second sensitivity andsecond compression point) that is different from the first dynamic rangeof the first signal. The apparatus may further comprise a third circuitadapted to generate an output signal related to a sum of the first andsecond signals. By adjusting the first and second dynamic ranges, anoverall dynamic range for the output signal of the companding apparatusmay be achieved.

FIG. 1 illustrates a block diagram of an exemplary compandor 100 inaccordance with an aspect of the disclosure. In summary, the compandor100 includes a plurality of non-linear devices, such as envelopedetectors, which are each configured to have distinct sensitivities andcompression points. The compression points are spaced apart atincreasing levels of input signal. In this manner, at a low input powerlevel, all of the envelope detectors (e.g., all three detectors) may beoperating to substantially square or detect the input signal. At amedium input power level, only a portion of the envelope detectors(e.g., two detectors) may be operating to substantially square or detectthe input signal. And, at a high input power level, only one of theenvelope detectors may operate to square or square the input signal. Theenvelope detectors may have distinct sensitivities in order to achieve aspecified dynamic range for the output signal of the compandor 100.

In particular, the compandor 100 comprises a first envelope detector102, a second envelope detector 104, and a third envelope detector 106,a first differential amplifier 108, a second differential amplifier 110,a third differential amplifier 112, and a summing device 114. Theenvelope detectors 102, 104, and 106 have inputs coupled together, andadapted to receive an input signal. The first, second, and thirdenvelope detectors 102, 104, and 106 have respective outputs coupled tothe positive inputs of the first, second, and third differentialamplifiers 108, 110, and 112. Reference voltages REF1, REF2, and REF3are applied respectively to the negative inputs of the differentialamplifiers 108, 110, and 112. The outputs of the differential amplifiers108, 110, and 112 are coupled to inputs of the summing device 114. Theoutput signal of the compandor 100 is generated at an output of thesumming device 114.

As previously discussed, the envelope detectors 102, 104, and 106 may beconfigured to have distinct dynamic ranges, e.g., distinct sensitivitiesand compression points. For example, the first envelope detector 102 maybe configured to have a relatively high sensitivity and a relatively lowcompression point. The second envelope detector 104 may be configured tohave a medium sensitivity and medium compression point. The thirdenvelope detector 106 may have a relatively low sensitivity and arelatively high compression point.

In this configuration, at a relatively low power level of the input RFsignal, the additive sensitivities of the envelope detectors 102, 104,and 106 including the relatively high sensitivity of the first envelopedetector 102 helps to detect the relatively low power level of the inputsignal. At a medium power level of the input RF signal, the firstenvelope detector 102 may be in compression, and does not significantlycontribute to the sensitivity of the compandor 100. Thus, in the mediuminput power range, the overall sensitivity of the compandor 100 is lowerthan its sensitivity in the low power range. This allows the mediumpower level signal to be detected, while preventing devices downstreamfrom going into compression. At a relatively high power level of theinput RF signal, both the first and second envelope detectors 102 and104 may be in compression, and do not significantly contribute to theoverall sensitivity of the compandor 100. Thus, in the high input powerrange, the overall sensitivity of the compandor is relatively low. Thisprevents devices downstream from going into compression.

The reference voltages REF1-3 applied respectively to the negativeinputs of the differential amplifiers 108, 110, and 112 allow foradjustment of the dynamic characteristic of the output of the compandor100. For instance, adjustment of any of the reference voltages appliedto the negative input of the differential amplifier effectively causes achange in the sensitivity and compression point of the correspondingprocessing segment (e.g., the envelope detector and correspondingdifferential amplifier). This is explained in more detail as follows.

FIG. 2 illustrates a graph of an exemplary input-output response of theexemplary compandor 100 in accordance with another aspect of thedisclosure. The x- or horizontal axis of the graph represents the powerlevel in dB of the input signal to the compandor 100. The y- or verticalaxis represents the output of the compandor 100, which could be in termsof a voltage or a current. Three (3) exemplary responses are shown onthe graph. The first response, shown as a solid line, may represent atypical input-output response of the compandor 100. As noted, the firstresponse includes three segments having distinct sensitivities: a highsensitivity at low input signal levels, a medium sensitivity at mediuminput signal levels, and a low sensitivity at high input signal levels.

The second response, shown as a dashed line, represents the input-outputresponse of the compandor 100 in response to an equal increase in all ofthe reference voltages REF 1-3. As noted, the effect of equallyincreasing all of the reference voltages is a rightward shift of theinput-output response. This, in effect, reduces the overall sensitivityof the compandor 100. Conversely, a reduction of all of the referencevoltages would result in a leftward shift of the input-output response,thereby increasing the overall sensitivity of the compandor 100.

The third response, shown as a dotted line, represents the input-outputresponse of the compandor 100 in response to an increase in onlyreference voltage REF 1 as applied to the negative input of thedifferential amplifier 108. As noted, the effect on only increasingreference voltage REF 1 is a rightward shift of the lower segmentincluding the first compression point of the input-output response ofthe compandor 100. Conversely, a decrease in only the reference voltageREF 1 would result in a leftward shift of the lower segment of theinput-output response. Each reference voltage REF 1-3 may be adjustedindependently of each other, in order to achieve a specifiedinput-output response for the compandor 100.

FIG. 3 illustrates a block diagram of another exemplary compandor 300 inaccordance with another aspect of the disclosure. In summary, thecompandor 300 operates similarly to the previously-discussed compandor100 in that it includes a plurality of parallel devices having distinctand specified sensitivities and compression points such that a specifieddynamic range for the output signal of the compandor 300 is achieved.

In particular, the compandor 300 comprises a non-linear or substantiallysquaring device 302, a first differential amplifier 304, a seconddifferential amplifier 306, a third differential amplifier 308, and asumming device 310. The squaring device 302 includes an input adapted toreceive an input signal, and an output coupled to the positive inputs ofthe differential amplifiers 304, 306, and 308. Reference voltages REF1-3 are applied respectively to the negative inputs of the differentialamplifiers 304, 306, and 308. The outputs of the differential amplifiers304, 306, and 308 are coupled to respective inputs of the summing device310. The output RF signal of the compandor 300 is generated at an outputof the summing device 310.

The differential amplifiers 304, 306, and 308 may be configured to havedistinct gains (sensitivities) and threshold points (compressionpoints). For example, the first differential amplifier 304 may beconfigured to have a relatively high gain and a relatively low thresholdpoint. The second differential amplifier 306 may be configured to have amedium gain and medium threshold point. The third differential amplifier308 may have a relatively low sensitivity and a relatively highcompression point.

Similar to the prior aspect, at a relatively low power level of theinput RF signal, the additive gains of the differential amplifiers 304,306, and 308 including the relatively high gain of the firstdifferential amplifier 304 helps to detect the relatively low powerlevel of the input signal. At a medium power level of the input RFsignal, the first differential amplifier 304 may be in compression, anddoes not significantly contribute to the gain of the compandor 300.Thus, in the medium input power range, the overall gain of the compandor300 is lower than the gain in the low power range. This allows themedium power level signal to be detected, while preventing devicesdownstream from going into compression. At a relatively high power levelof the input signal, both the first and second differential amplifiers304 and 306 may be in compression, and do not significantly contributeto the overall gain of the compandor 300. Thus, in the high input powerrange, the overall gain of the compandor is relatively low. Thisprevents devices downstream from going into compression.

Also, similar to the prior aspect, the reference voltages REF1-3 appliedrespectively to the negative inputs of the differential amplifiers 304,306, and 308 allow for adjustment of the dynamic characteristic of theoutput of the compandor 300. For instance, adjustment of any of thereference voltages applied to the negative input of the differentialamplifier effectively causes a change in the corresponding dynamicrange, as previously discussed in connection with the prior aspect.

FIG. 4 illustrates a block diagram of yet another exemplary compandor400 in accordance with another aspect of the disclosure. In summary, thecompandor 400 includes a plurality of differential transistor pairsconfigured respectively as non-linear or substantially squaring devices,and a programmable reference voltage device for setting up respectivesource voltages for the differential transistor pairs. The differentialtransistor pairs may be set up with different sensitivities andcompression points to achieve a desired dynamic range for the output ofthe compandor 400. Additionally, the programmable reference voltagedevice may be configured to generate source voltages for the respectivedifferential transistor pairs to provide adjustment to the dynamic rangeof the output of the compandor 400.

In particular, the compandor 400 comprises a pre-amplifier 402, aplurality of non-linear or substantially squaring devices configured asdifferential transistor pairs 404, 406, and 408, a plurality of currentsources 410, 412, and 414, a plurality of reference voltage transistorsM41, M42, and M43, and a programmable reference level device 416. Thepre-amplifier 402 includes an input adapted to receive an input RFsignal, and differential outputs coupled to the gates of eachdifferential transistor pairs 404, 406, and 408. The differentialtransistor pairs 404, 406, and 408 include respectively a firstdifferential transistor (M11, M21, and M31) and a second differentialtransistor (M12, M22, and M32). The current sources 410, 412, and 414are coupled between the respective sources of the differentialtransistor pairs 404, 406, and 408, and Vss potential rail, which may beat ground potential.

The programmable reference level device 416 includes outputs coupled tothe gates of transistors M41, M42, and M43. The sources of transistorsM41, M42, and M43 are respectively coupled to the sources of thedifferential transistor pairs 404, 406, and 408. The output of thecompandor 400 is taken as a differential current ΔI between the drainsof the differential transistor pairs 404, 406, and 408, and the drainsof the reference voltage transistors M41, M42, and M43.

The differential transistor pairs 404, 406, and 408 may be configured tohave distinct sensitivities and compression points. For instance, byscaling the width to length aspect ratio of the transistors in eachdifferential transistor pair, compression break points can be achievedacross the dynamic range of the output of the compandor 400. As anexample, the first differential transistor pair 404 may be configured tohave a relatively high sensitivity and a relatively low compressionpoint. The second differential transistor pair 406 may be configured tohave a medium sensitivity and medium compression point. The thirddifferential transistor pair 406 may have a relatively low sensitivityand a relatively high compression point.

Similar to the prior aspects, at a relatively low power level of theinput RF signal, the additive sensitivities of the differentialtransistor pairs 404, 406, and 408 including the relatively high gain ofthe first differential transistor pair 404 helps to detect therelatively low power level of the input signal. At a medium power levelof the input RF signal, the first differential transistor pair 404 maybe in compression, and does not significantly contribute to the overallsensitivity of the compandor 400. Thus, in the medium input power range,the overall sensitivity of the compandor 400 is lower than thesensitivity in the low power range. This allows the medium power levelsignal to be detected, while preventing devices downstream from goinginto compression. At a relatively high power level of the input RFsignal, both the first and second differential transistor pairs 404 and406 may be in compression, and do not significantly contribute to theoverall sensitivity of the compandor 400. Thus, in the high input powerrange, the overall sensitivity of the compandor is relatively low. Thisprevents devices downstream from going into compression.

Also, similar to the prior aspects, the reference voltages REF1-3applied respectively to the sources of the differential transistor pairs404, 406, and 408 allow for adjustment of the dynamic characteristic ofthe output of the compandor 400. For instance, adjustment of any of thereference voltages applied to the source of the correspondingdifferential transistor effectively causes a change in the sensitivityand compression, as previously discussed in connection with the prioraspects.

FIG. 5 illustrates a block diagram of an exemplary communications device500 including an exemplary receiver in accordance with another aspect ofthe disclosure. The communications device 500 may be particularly suitedfor sending and receiving data to and from other communications devices.The communications device 500 comprises an antenna 502, a Tx/Rxisolation device 504, a front-end receiver portion 506, anRF-to-baseband receiver portion 508, a baseband unit 510, abaseband-to-RF transmitter portion 512, a transmitter 514, a datareceiver 516, and a data generator 518. The receiver 506 may beconfigured to include at least some of the components of the compandorspreviously discussed.

In operation, the data processor 516 may receive data from a remotecommunications device via the antenna 502 which picks up the RF signalfrom the remote communications device, the Tx/Rx isolation device 504which sends the signal to the front-end receiver portion 506, thereceiver front-end 506 which amplifies the received signal, theRF-to-baseband receiver portion 508 which converts the RF signal into abaseband signal, and the baseband unit 510 which processes the basebandsignal to determine the received data. The data receiver 516 may thenperform one or more defined operations based on the received data. Forexample, the data processor 516 may include a microprocessor, amicrocontroller, a reduced instruction set computer (RISC) processor, adisplay, an audio device, such as a headset, including a transducer suchas speakers, a medical device, a shoe, a watch, a robotic or mechanicaldevice responsive to the data, a user interface, such as a display, oneor more light emitting diodes (LED), etc.

Further, in operation, the data generator 518 may generate outgoing datafor transmission to another communications device via the baseband unit510 which processes the outgoing data into a baseband signal fortransmission, the baseband-to-RF transmitter portion 512 which convertsthe baseband signal into an RF signal, the transmitter 514 whichconditions the RF signal for transmission via the wireless medium, theTx/Rx isolation device 504 which routes the RF signal to the antenna 502while isolating the input to the receiver front-end 506, and the antenna502 which radiates the RF signal to the wireless medium. The datagenerator 518 may be a sensor or other type of data generator. Forexample, the data generator 518 may include a microprocessor, amicrocontroller, a RISC processor, a keyboard, a pointing device such asa mouse or a track ball, an audio device, such as a headset, including atransducer such as a microphone, a medical device, a shoe, a robotic ormechanical device that generates data, a user interface, such as adisplay, one or more light emitting diodes (LED), etc.

FIG. 6 illustrates a block diagram of an exemplary communications device600 including an exemplary receiver in accordance with another aspect ofthe disclosure. The communications device 600 may be particularly suitedfor receiving data from other communications devices. The communicationsdevice 600 comprises an antenna 602, a front-end receiver 604, anRF-to-baseband transmitter portion 606, a baseband unit 608, and a datareceiver 610. The receiver 604 may be configured to include at leastsome of the components of the compandors previously discussed.

In operation, the data processor 610 may receive data from a remotecommunications device via the antenna 602 which picks up the RF signalfrom the remote communications device, the receiver front-end 604 whichamplifies the received signal, the RF-to-baseband receiver portion 606which converts the RF signal into a baseband signal, and the basebandunit 608 which processes the baseband signal to determine the receiveddata. The data receiver 610 may then perform one or more definedoperations based on the received data. For example, the data processor610 may include a microprocessor, a microcontroller, a reducedinstruction set computer (RISC) processor, a display, an audio device,such as a headset, including a transducer such as speakers, a medicaldevice, a shoe, a watch, a robotic or mechanical device responsive tothe data, a user interface, such as a display, one or more lightemitting diodes (LED), etc.

FIG. 7A illustrates different channels (channels 1 and 2) defined withdifferent pulse repetition frequencies (PRF) as an example of a pulsemodulation that may be employed in any of the communications systemsdescribed herein. Specifically, pulses for channel 1 have a pulserepetition frequency (PRF) corresponding to a pulse-to-pulse delayperiod 702. Conversely, pulses for channel 2 have a pulse repetitionfrequency (PRF) corresponding to a pulse-to-pulse delay period 704. Thistechnique may thus be used to define pseudo-orthogonal channels with arelatively low likelihood of pulse collisions between the two channels.In particular, a low likelihood of pulse collisions may be achievedthrough the use of a low duty cycle for the pulses. For example, throughappropriate selection of the pulse repetition frequencies (PRF),substantially all pulses for a given channel may be transmitted atdifferent times than pulses for any other channel.

The pulse repetition frequency (PRF) defined for a given channel maydepend on the data rate or rates supported by that channel. For example,a channel supporting very low data rates (e.g., on the order of a fewkilobits per second or Kbps) may employ a corresponding low pulserepetition frequency (PRF). Conversely, a channel supporting relativelyhigh data rates (e.g., on the order of a several megabits per second orMbps) may employ a correspondingly higher pulse repetition frequency(PRF).

FIG. 7B illustrates different channels (channels 1 and 2) defined withdifferent pulse positions or offsets as an example of a modulation thatmay be employed in any of the communications systems described herein.Pulses for channel 1 are generated at a point in time as represented byline 706 in accordance with a first pulse offset (e.g., with respect toa given point in time, not shown). Conversely, pulses for channel 2 aregenerated at a point in time as represented by line 708 in accordancewith a second pulse offset. Given the pulse offset difference betweenthe pulses (as represented by the arrows 710), this technique may beused to reduce the likelihood of pulse collisions between the twochannels. Depending on any other signaling parameters that are definedfor the channels (e.g., as discussed herein) and the precision of thetiming between the devices (e.g., relative clock drift), the use ofdifferent pulse offsets may be used to provide orthogonal orpseudo-orthogonal channels.

FIG. 7C illustrates different channels (channels 1 and 2) defined withdifferent timing hopping sequences modulation that may be employed inany of the communications systems described herein. For example, pulses712 for channel 1 may be generated at times in accordance with one timehopping sequence while pulses 714 for channel 2 may be generated attimes in accordance with another time hopping sequence. Depending on thespecific sequences used and the precision of the timing between thedevices, this technique may be used to provide orthogonal orpseudo-orthogonal channels. For example, the time hopped pulse positionsmay not be periodic to reduce the possibility of repeat pulse collisionsfrom neighboring channels.

FIG. 7D illustrates different channels defined with different time slotsas an example of a pulse modulation that may be employed in any of thecommunications systems described herein. Pulses for channel L1 aregenerated at particular time instances. Similarly, pulses for channel L2are generated at other time instances. In the same manner, pulse forchannel L3 are generated at still other time instances. Generally, thetime instances pertaining to the different channels do not coincide ormay be orthogonal to reduce or eliminate interference between thevarious channels.

It should be appreciated that other techniques may be used to definechannels in accordance with a pulse modulation schemes. For example, achannel may be defined based on different spreading pseudo-random numbersequences, or some other suitable parameter or parameters. Moreover, achannel may be defined based on a combination of two or more parameters.

FIG. 8 illustrates a block diagram of various ultra-wide band (UWB)communications devices communicating with each other via variouschannels in accordance with another aspect of the disclosure. Forexample, UWB device 1 802 is communicating with UWB device 2 804 via twoconcurrent UWB channels 1 and 2. UWB device 802 is communicating withUWB device 3 806 via a single channel 3. And, UWB device 3 806 is, inturn, communicating with UWB device 4 808 via a single channel 4. Otherconfigurations are possible. The communications devices may be used formany different applications, and may be implemented, for example, in aheadset, microphone, biometric sensor, heart rate monitor, pedometer,EKG device, watch, shoe, remote control, switch, tire pressure monitor,or other communications devices.

FIG. 9 illustrates a block diagram of another exemplary compandor 900 inaccordance with another aspect of the disclosure. The compandor 900comprises a first signal generating module 902 adapted to generate afirst signal from an input signal, wherein the first signal has a firstdynamic range. The compandor 900 further comprises a second signalgenerating module 904 adapted to generate a second signal from the inputsignal, wherein the second signal has a second dynamic range that isdifferent from the first dynamic range.

Any of the above aspects of the disclosure may be implemented in manydifferent devices. For example, in addition to medical applications asdiscussed above, the aspects of the disclosure may be applied to healthand fitness applications. Additionally, the aspects of the disclosuremay be implemented in shoes for different types of applications. Thereare other multitude of applications that may incorporate any aspect ofthe disclosure as described herein.

Various aspects of the disclosure have been described above. It shouldbe apparent that the teachings herein may be embodied in a wide varietyof forms and that any specific structure, function, or both beingdisclosed herein is merely representative. Based on the teachings hereinone skilled in the art should appreciate that an aspect disclosed hereinmay be implemented independently of any other aspects and that two ormore of these aspects may be combined in various ways. For example, anapparatus may be implemented or a method may be practiced using anynumber of the aspects set forth herein. In addition, such an apparatusmay be implemented or such a method may be practiced using otherstructure, functionality, or structure and functionality in addition toor other than one or more of the aspects set forth herein. As an exampleof some of the above concepts, in some aspects concurrent channels maybe established based on pulse repetition frequencies. In some aspectsconcurrent channels may be established based on pulse position oroffsets. In some aspects concurrent channels may be established based ontime hopping sequences. In some aspects concurrent channels may beestablished based on pulse repetition frequencies, pulse positions oroffsets, and time hopping sequences.

Those of skill in the art would understand that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

Those of skill would further appreciate that the various illustrativelogical blocks, modules, processors, means, circuits, and algorithmsteps described in connection with the aspects disclosed herein may beimplemented as electronic hardware (e.g., a digital implementation, ananalog implementation, or a combination of the two, which may bedesigned using source coding or some other technique), various forms ofprogram or design code incorporating instructions (which may be referredto herein, for convenience, as “software” or a “software module”), orcombinations of both. To clearly illustrate this interchangeability ofhardware and software, various illustrative components, blocks, modules,circuits, and steps have been described above generally in terms oftheir functionality. Whether such functionality is implemented ashardware or software depends upon the particular application and designconstraints imposed on the overall system. Skilled artisans mayimplement the described functionality in varying ways for eachparticular application, but such implementation decisions should not beinterpreted as causing a departure from the scope of the presentdisclosure.

The various illustrative logical blocks, modules, and circuits describedin connection with the aspects disclosed herein may be implementedwithin or performed by an integrated circuit (“IC”), an access terminal,or an access point. The IC may comprise a general purpose processor, adigital signal processor (DSP), an application specific integratedcircuit (ASIC), a field programmable gate array (FPGA) or otherprogrammable logic device, discrete gate or transistor logic, discretehardware components, electrical components, optical components,mechanical components, or any combination thereof designed to performthe functions described herein, and may execute codes or instructionsthat reside within the IC, outside of the IC, or both. A general purposeprocessor may be a microprocessor, but in the alternative, the processormay be any conventional processor, controller, microcontroller, or statemachine. A processor may also be implemented as a combination ofcomputing devices, e.g., a combination of a DSP and a microprocessor, aplurality of microprocessors, one or more microprocessors in conjunctionwith a DSP core, or any other such configuration.

It is understood that any specific order or hierarchy of steps in anydisclosed process is an example of a sample approach. Based upon designpreferences, it is understood that the specific order or hierarchy ofsteps in the processes may be rearranged while remaining within thescope of the present disclosure. The accompanying method claims presentelements of the various steps in a sample order, and are not meant to belimited to the specific order or hierarchy presented.

The steps of a method or algorithm described in connection with theaspects disclosed herein may be embodied directly in hardware, in asoftware module executed by a processor, or in a combination of the two.A software module (e.g., including executable instructions and relateddata) and other data may reside in a data memory such as RAM memory,flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a harddisk, a removable disk, a CD-ROM, or any other form of computer-readablestorage medium known in the art. A sample storage medium may be coupledto a machine such as, for example, a computer/processor (which may bereferred to herein, for convenience, as a “processor”) such theprocessor can read information (e.g., code) from and write informationto the storage medium. A sample storage medium may be integral to theprocessor. The processor and the storage medium may reside in an ASIC.The ASIC may reside in user equipment. In the alternative, the processorand the storage medium may reside as discrete components in userequipment. Moreover, in some aspects any suitable computer-programproduct may comprise a computer-readable medium comprising codesrelating to one or more of the aspects of the disclosure. In someaspects a computer program product may comprise packaging materials.

While the invention has been described in connection with variousaspects, it will be understood that the invention is capable of furthermodifications. This application is intended to cover any variations,uses or adaptation of the invention following, in general, theprinciples of the invention, and including such departures from thepresent disclosure as come within the known and customary practicewithin the art to which the invention pertains.

1. An apparatus, comprising: a first circuit adapted to generate a first signal from an input signal, wherein the first signal has a first dynamic range; and a second circuit adapted to generate a second signal from the input signal, wherein the second signal has a second dynamic range that is different from the first dynamic range of the first signal.
 2. The apparatus of claim 1, further comprising a third circuit adapted to generate a third signal related to a sum of the first and second signals.
 3. The apparatus of claim 1, wherein the first signal is non-linearly related to the input signal.
 4. The apparatus of claim 1, wherein the first circuit is configured to have a first sensitivity or gain in generating the first signal from the input signal.
 5. The apparatus of claim 4, wherein the second circuit is configured to have a second sensitivity or gain in generating the second signal from the input signal, and further wherein the second sensitivity or gain of the second circuit is different than the first sensitivity or gain of the first circuit.
 6. The apparatus of claim 1, wherein the first circuit is configured to have a first compression point or threshold.
 7. The apparatus of claim 6, wherein the second circuit is configured to have a second compression point or threshold, and further wherein the second compression point or threshold of the second circuit is different than the first compression point or threshold of the first circuit.
 8. The apparatus of claim 1, further comprising a third circuit for adjusting the first or second dynamic range.
 9. The apparatus of claim 8, wherein the third circuit is adapted to provide a reference voltage or current to the first or second circuit.
 10. The apparatus of claim 9, wherein the third circuit comprises a programmable reference level device adapted to generate the reference voltage or current.
 11. The apparatus of claim 1, wherein the first or second circuit comprises an envelope detector, a squaring device, a differential transistor pair, or a differential amplifier.
 12. The apparatus of claim 1, wherein the first circuit comprises a first transistor pair with transistors having a first size, and further wherein the second circuit comprises a second transistor pair with transistors having a second size different than the first size of the transistors of the first transistor pair.
 13. The apparatus of claim 12, further comprising first and second current sources adapted to provide first and second reference currents for the first and second transistor pairs.
 14. A method of processing an input signal, comprising: generating a first signal from the input signal, wherein the first signal has a first dynamic range; and generating a second signal from the input signal, wherein the second signal has a second dynamic range that is different from the first dynamic range of the first signal.
 15. The method of claim 14, further comprising combining the first and second signals to generate a third signal.
 16. The method of claim 14, wherein the first signal is non-linearly related to the input signal.
 17. The method of claim 14, wherein generating the first signal comprises detecting the input signal with a first sensitivity or gain to generate the first signal.
 18. The method of claim 17, wherein generating the second signal comprises detecting the input signal with a second sensitivity or gain to generate the second signal, and further wherein the second sensitivity or gain is different than the first sensitivity or gain.
 19. The method of claim 14, wherein generating the first signal comprises generating the first signal not substantially beyond a first compression or threshold level.
 20. The method of claim 19, wherein generating the second signal comprises generating the second signal not substantially beyond a second compression or threshold level, and further wherein the second compression or threshold level is different than the first compression or threshold level.
 21. The method of claim 14, further comprising adjusting the first or second dynamic range.
 22. The method of claim 21, wherein adjusting the first or second dynamic range comprises generating a reference voltage or current, respectively.
 23. The method of claim 22, wherein generating the reference voltage or current comprises activating a programmable reference level device.
 24. The method of claim 14, wherein generating the first or second signal comprises envelope detecting or substantially squaring the input signal.
 25. The method of claim 14, wherein generating the first signal comprises applying the input signal to a first transistor pair with transistors of a first size, and further wherein generating the second signal comprises applying the input signal to a second transistor pair with transistors of a second size different than the first size of the transistors of the first transistor pair.
 26. The method of claim 25, further comprising providing first and second reference currents for the first and second transistor pairs.
 27. An apparatus, comprising: a first means for generating a first signal from an input signal, wherein the first signal has a first dynamic range; and a second means for generating a second signal from the input signal, wherein the second signal has a second dynamic range that is different from the first dynamic range of the first signal.
 28. The apparatus of claim 27, further comprising means for combining the first and second signals to generate a third signal.
 29. The apparatus of claim 27, wherein the first signal is non-linearly related to the input signal.
 30. The apparatus of claim 27, wherein the first generating means is configured to have a first sensitivity or gain in generating the first signal from the input signal.
 31. The apparatus of claim 30, wherein the second generating means is configured to have a second sensitivity or gain in generating the second signal from the input signal, and further wherein the second sensitivity or gain of the second generating means is different than the first sensitivity or gain of the first generating means.
 32. The apparatus of claim 27, wherein the first generating means is configured to have a first compression point or threshold.
 33. The apparatus of claim 32, wherein the second generating means is configured to have a second compression point or threshold, and further wherein the second compression point of threshold of the second generating means is different than the first compression point or threshold of the first generating means.
 34. The apparatus of claim 27, further comprising a means for adjusting the first or second dynamic range.
 35. The apparatus of claim 34, wherein the dynamic range adjusting means is adapted to provide a reference voltage or current to the first or second generating means, respectively.
 36. The apparatus of claim 35, wherein the dynamic range adjusting means comprises a programmable reference level device adapted to generate the reference voltage or current.
 37. The apparatus of claim 27, wherein the first or second generating means comprises an envelope detector, a squaring device, a differential transistor pair, or a differential amplifier.
 38. The apparatus of claim 27, wherein the first generating means comprises a first transistor pair with transistors of a first size, and further wherein the second generating means comprises a second transistor pair with transistors of a second size different than the first size of the transistors of the first transistor pair.
 39. The apparatus of claim 38, further comprising means for generating first and second reference currents for the first and second transistor pairs.
 40. The apparatus of claim 27, wherein the first or second generating means is adapted to have a fractional bandwidth on the order of 20% or more, a bandwidth on the order of 500 MHz or more, or a fractional bandwidth on the order of 20% or more and a bandwidth on the order of 500 MHz or more.
 41. A headset, comprising: a first circuit adapted to generate a first signal from an input signal, wherein the first signal has a first dynamic range; a second circuit adapted to generate a second signal from the input signal, wherein the second signal has a second dynamic range that is different from the first dynamic range of the first signal; and a transducer adapted to generate sound based on the first and second signals.
 42. A watch, comprising: a first circuit adapted to generate a first signal from an input signal, wherein the first signal has a first dynamic range; a second circuit adapted to generate a second signal from the input signal, wherein the second signal has a second dynamic range that is different from the first dynamic range of the first signal; and a user interface adapted to provide an indication based on the first and second signals.
 43. A sensing device, comprising: a first circuit adapted to generate a first signal from an input signal, wherein the first signal has a first dynamic range; a second circuit adapted to generate a second signal from the input signal, wherein the second signal has a second dynamic range that is different from the first dynamic range of the first signal; and a sensor adapted to generate data based on the first and second signals. 